Control system



Dec. 18, 1928. 1,695,856

A. A. PONSONBY CONTROL SYSTEM Filed Feb. 2L 1927 WITNESSES: INVENTORAmos A. Pansonby Patented Dec. 18, 1928.

umrso STATES PATENT OFFICE.

AMOS ALBERT PONSON BY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELEGTBIG & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

CONTROL SYSTEM.

Application filed February 21, 1927. Serial is. 169,964.

This invention relates to motor-control systems and primarily to controls stems for,

use on motor-driven vehicles, suc as mine ears andthe like. I p

The object of the invention generally stated, is the provision of acontro system for motor-driven vehicles that shall be simple andefficient in Operation and readily and'economically manufactured. I .1 1

A more specific object of the invention is to provide for opening thecontrol circuits of a motor-control system utilized for controlling amotor-driven vehicle, when'the operator leaves the control station.

It is also an object of the invention to provide a control system for amotor, which requires that the controller drum be moved to its offposition before controlcircuits that have been interrupted may be re-established.

Other objects of the invention will, in part, be obvious, and will, inpart, appear hereinafter. 1

The invention is disclosed in the embodiment thereof shown in theaccompanying drawing and comprises the features of construction,combination of elements, and ar- 1 rangement'of parts that will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the claims.

For a fuller understandingof the nature and objects of the invention,reference should be had to the following detailed description, taken inconnection with the accompanying drawing, in which, I

Fig. 1 is a view, in side elevation, of a mine car equipped with asafety attachment which constitutesthe subject matter of this invention,and I Fig. 2 is a diagram of the circuit connections of a control systemarranged inaccordance with this invention.

Referring now to the drawing, 10 designates, generally, a mine car ofany well-known 7 construction which may be operated by means of a motorof any suitable type, such, for example, as the series motor 11 shown inFig. 2. In vehicles of this type, a cab, such as illustrated at 12, isprovided for the operator.

It often happens, in the operation of vehicles of this type, that thepower fails and the vehicle is brought to a stop with the controller setin its on position. Under such conditions, the operator may be requiredto leave the vehicle in order to make an inspection of the power systemor repairs, and, if he 13 negligent, he may leave the vehicle with thecontroller set in its on position. Accordingly, if the power supply issuddenly rc-established, there is apossibility that the vehicle may beset inop'eration to move along the track without an operator.

I In order to prevent the possibility of starting a vehicle of this typeupon the re-estabhshment of the power supply and when the operator isnot in his cab, a safety switch 13 is provided. In this particularembodiment of the invention, a foot-operated switch is disposed in thecab in someposition which requires the operator to be located athisfpost before he can actuate it.

The operation of the safety switch will be understood from thefollowingdescription of the operation of the motor 11. Assuming that it isdesired to operate the vehicle 10 and that the operator has closed thesafety switch 13 and actuated the controller 14 to advance thecontroller drum 15 to position b, it will be understood that themanually o erable switch 16 will be closed when the ve iicle is put inservice and will remain closed until the vehicle is returned to thecarshedor some other place for parking.

Upon the closure ofthe switch 13, current flows from the trolleyconductor 17, through the trolley pole 18, conductor 19, switch 13,

the actuating coil 20 of the relay 21, and resistorv22, to the groundat23. Therefore,

upon the closure of the safety switch 13, the actuating circuit for therelay 21 is closed and the contact member 24:, carried by the relay, isactuated to close the actuating circuit of theline switch 25.

As will be observed, the actuating circuit for the line switch 25extends from the tro1- ley conductor 17 through trolley pole 18,conductor 19, switch 16, conductor 26, contact fingers 27 and 28,bridged by the contact segment 29 of the controller drum 15, shunt 30,

contact fingers 31 and 32, bridged by the contact segment 33, conductor34, the actuating coil 35 of the line switch 25, conductor 36, contactplate 24, carried by the relay 21, and

conductor 37, to theground at 23. In this manner, the motor circuit isclosed, and current flows from the trolley pole 18, through lay.Therefor until the dri 'l it willbe impossihle to e'ltcct the operationconductor 38, switch 525 and the armature and held of the series motor11, to the ground at 39 Assuming now that, for any reason, the powersupply through the trolley conductor 1T tails, that the controller druml5 standing in position o and that h rperator (li5- mounts from the cab12. the su ii' 12}. which om-tun; it ot the ,7 drops to its actuatingcircuit is normally hi i tions to interrupt the actuating c relayFurther. th open position, hr a 111 l contact segment 2) throu 1 contactlinger '31, conductor 1, con act plate 40, a ried hy L the relay 21,conduct 22, to the ground at L;

Assume now, that the position in the cal) and c since the drum l5 in pinind the resistor 11 Z), the a t iat- -in coil 20 ot the relay isconnected in parallel with the slurit circuit he traced, and thecurrent, which flows in the re estahlisuetl relay actuating circuit,will he insuliicientto e ti'ect the operat' of the reu is returned "c :115 to its oii position to open he shunt circuit,

- of the relay 21.

disposed in an inaccecsi di'flieult for any one, xc ed in his cal), toactuate danger of the vehicle o1 unless the operator Since certain chan;made in the ahoye construction. and (.1 ments of the m :nlion may JGdeparting from the scope tl er ed that all matter contain- 1L scriptionor shown in the drawing shall he interpreted and not in a limitingsense.

'I claim as my inrention:

1. In a control system for a vided with a propelling motor, in tion, aline switch for controlling the z to operator seathus, the is no I :1operation tion of the motor, a line-switch-actuatin circuit-toroperating the line switch, a ilru in for controlling the energization ofthe lines\ itch-actuating circuit, a relay disposed for interrupting theline-switch-actuating circuit, an actuating circuit for the relay, asafety switch for controlling,' the relay: cluating circuit, and a shuntconnected to pre- Ycnt the energization of the relzrr-actuatin circuitby the closure of the satay switc i when the drum in an active position.

2. In a control system for a vehicle provided with a propelling motor,in combination, a line switch for -ontrolling the operation of themotor, a line-switch-actrating circuit including a drum and a relay, anactuating circuit for the relay, a safety switch normally biased towardan open position for controlling the relay-actuating: circuit, and ashunt controlled by the relay for n'cventing the energization of therelay to cl. :1. the lineswitch-actuating circuit upon the operation ofthe safety switch when the drum in an active position.

3. In a control system for a vehicle provided with a propelling motor,in combination, a line switch for controlling the operation of themotor, a line switch actuating circuit, a relay pri'wided with anactuating coil for controlling the line switch circuit, a safety switcnfor controlling the operathm of the re ay, means for establishing acircuit to shunt the ac mating coil ot the relay and the safety switchto prevent the o eration of the relay in response to the closure of thesafety switch, and means for interrupting: the shunt circuit to permitthe operation oi the relay upon the closiiire of the safety switch.

4;. In a control system for a vehicle proided with a propelling motor.in -om ination, a controller for the motor, a line switch forcontrolling the ope 'ation of the motor, a relay provided with anactuating coil for ci'introlling the line switch circuit. a safetyswitch for con rolling the ope'ation oi the relay and means co-o pe'atire with the controller to establish a circuit to shunt theactuating" coil of the relay and the safety switch to prevent theoperation of the r a) n r sponse to the closure of the safety tel saidcontroller being disposed to interrupt the shunt circuit when thrown toits oil position to permit the operation of the relay upon the closureof the safety switch.

In testimony whereof, I have hereunto subscribed my name this 16th dayof Pol:- ruary, 1927.

AMOS ALBERT PONSONBY.

